It is provided a Near Infrared Sensitive (NIR-sensitive) nanoparticle complex comprising a NIR-sensitive nanoparticle and surfactant(s) adsorbed on the nanoparticle, wherein the surfactant is at least one surfactant selected from: ##STR00001## wherein X=1-9; Y=0-9; n=0-9; Z=1-9; W=0-9; m=0-9; each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4, if present, is H, substituted or unsubstituted C.sub.1-C.sub.6 alkyl, substituted or unsubstituted C.sub.1-C.sub.6 aryl, HS, COOH, NH.sub.2 or OH; R.sup.5 is COOH, NH.sub.2 or OH; with the proviso that n+m is <10; (b) an amino acid having the structure in (a), wherein X=1; Y=2; Z=1; W=1; R.sup.1, R.sup.2 and R.sup.4 are not present; R.sup.3 is NH.sub.2; and R.sup.5 is COOH; or (c) a peptide, wherein the peptide comprise at least one amino acid (b). Further, it is provided a NIR-sensitive nanoparticle complex(es) having biomolecule(s), for example drug(s), loaded on the surfactant(s).